1. Field of the Invention
The present invention relates to a clamping mechanism for fixing a wafer-accommodating FOUP to a mounting base.
2. Description of Related Art
A FOUP (Front Open Unified Pod) is used for accommodating and conveying wafers for an electronic device or storing these in a clean room. Then, in order to communicatively connect the interior of the FOUP with the interior of a semiconductor manufacturing device, the FOUP is fixed to an interface mechanism, which is called a FOUP opener (or a load port). Furthermore, at the FOUP opener, the FOUP is docked to a port door, which shields a communication port leading to the semiconductor manufacturing device, by which the interior of the FOUP and the interior of the semiconductor manufacturing device are kept airtight and communicatively connected with each other, the interiors of the FOUP and the semiconductor manufacturing device are kept at a high degree of cleanliness, while the exteriors thereof are kept at a low degree of cleanliness, thus this makes it possible to reduce construction and operation costs of the clean room.
A FOUP opener is required to have measures for preventing the contamination of semiconductors by foreign fine particles. For this reason, a mounting base at which a FOUP is installed and fixed is moved from an undocking position to a docking position, by which the FOUP is kept airtight and docked to a port door. Then, in order to bring in and out wafers, a lid portion of the FOUP and the port door are opened or closed. Furthermore, in this instance, it is necessary to fix the FOUP on the mounting base of the FOUP opener by such a sufficient force to keep an airtight state between the FOUP and the semiconductor manufacturing device. Regarding the above-described fixture of the FOUP, the SEMI (Semiconductor Equipment and Materials International) standards specify that a FOUP clamping mechanism is installed on a FOUP opener. The standards also specify a configuration of recesses for a clamping mechanism on the bottom of the FOUP, a clamping force necessary for the clamping mechanism or the like. Then, as examples of the clamping mechanism according to these standards, known are technologies disclosed in (1) Japanese Published Unexamined Patent Application No. 2003-297903, (2) Japanese Published Unexamined Patent Application No. 2005-129706 and (3) Japanese Published Unexamined Patent Application No. 2004-140011. In the technologies of Patent Documents (1) and (2), a clamping pawl is hooked on the clamping recess at the bottom of the FOUP and also the pawl is lowered, by which the pawl is pressed to the mounting base of the FOUP opener to fix the FOUP.
Furthermore, Patent Document (3) discloses a FOUP opener capable of adjusting a direction at which a FOUP is installed. In the FOUP opener, a notch is formed at a mounting base (a connecting plate and a container mounting piece) and a cylindrical portion, which is able to rotate, ascend and descend, is arranged into the notch. A mounting plate, on which the FOUP is mounted, is provided at the upper end of the cylindrical portion. Then, a motor for actuating the cylindrical portion is provided inside a supporting piece installed below the mounting base. Since this prior art is constituted as described above, eliminated is a necessity for providing a large device (a FOUP handling hand), thus this makes it possible to adjust a FOUP installing direction and position correctly a drawing port of the FOUP with respect to a semiconductor manufacturing device.